The most widely used anti-bot technique is the use of CAPTCHA, which is a form of Turing test used to distinguish between a human user and a less-sophisticated AI-powered bot, by the use of graphically-encoded human-readable text. Examples of providers include Recaptcha, and commercial companies such as Minteye, Solve Media, and NuCaptcha. Captchas, however, are not foolproof in preventing bots as they can often be circumvented by computer character recognition, security holes, and even by outsourcing captcha solving to cheap laborers.

“Beware though, bots have the illusion of simplicity on the front end but there are many hurdles to overcome to create a great experience. So much work to be done. Analytics, flow optimization, keeping up with ever changing platforms that have no standard. For deeper integrations and real commerce like Assist powers, you have error checking, integrations to APIs, routing and escalation to live human support, understanding NLP, no back buttons, no home button, etc etc. We have to unlearn everything we learned the past 20 years to create an amazing experience in this new browser.” — Shane Mac, CEO of Assist
Simple chatbots work based on pre-written keywords that they understand. Each of these commands must be written by the developer separately using regular expressions or other forms of string analysis. If the user has asked a question without using a single keyword, the robot can not understand it and, as a rule, responds with messages like “sorry, I did not understand”.
Last, but not least coming in with the bot platform for business is FlowXO, which creates bots for Messenger, Slack, SMS, Telegraph and the web. This platform allows for creating various flexibility in bots by giving you the option to create a fully automated bot, human, or a hybrid of both. ChatBot expert Murray Newlands commented that "Where 10 years ago every company needed a website and five  years ago every company needed an app, now every company needs to embrace messaging with AI and chatbots."

Amplify your Facebook advertising, content reach and customer service by using this one of the best messenger marketing tools will surely do your business good. Formerly known as ChattyPeople, this bot tool can be easily integrated without any coding knowledge. MobileMonkey integrates with tools such as Shopify you can monetize your fan page in simpler ways than you thought.

In 1950, Alan Turing's famous article "Computing Machinery and Intelligence" was published,[8] which proposed what is now called the Turing test as a criterion of intelligence. This criterion depends on the ability of a computer program to impersonate a human in a real-time written conversation with a human judge, sufficiently well that the judge is unable to distinguish reliably—on the basis of the conversational content alone—between the program and a real human. The notoriety of Turing's proposed test stimulated great interest in Joseph Weizenbaum's program ELIZA, published in 1966, which seemed to be able to fool users into believing that they were conversing with a real human. However Weizenbaum himself did not claim that ELIZA was genuinely intelligent, and the introduction to his paper presented it more as a debunking exercise:

Despite the fact that ALICE relies on such an old codebase, the bot offers users a remarkably accurate conversational experience. Of course, no bot is perfect, especially one that’s old enough to legally drink in the U.S. if only it had a physical form. ALICE, like many contemporary bots, struggles with the nuances of some questions and returns a mixture of inadvertently postmodern answers and statements that suggest ALICE has greater self-awareness for which we might give the agent credit.
There has been a great deal of controversy about the use of bots in an automated trading function. Auction website eBay has been to court in an attempt to suppress a third-party company from using bots to traverse their site looking for bargains; this approach backfired on eBay and attracted the attention of further bots. The United Kingdom-based bet exchange Betfair saw such a large amount of traffic coming from bots that it launched a WebService API aimed at bot programmers, through which it can actively manage bot interactions.
This form of artificial intelligence was first developed by MIT Professor Joseph Weizenbaum in the 1960’s and named ELIZA. It wasn’t until 2011, when chatbots had a resurgence with the inception of WeChat in China. Customers could create chatbots on this platform and interact with one another seamlessly. In 2016, Facebook introduced its own chatbots which paved the way for this form of artificial intelligence to enter and interact with mainstream media consumption.
Develop intelligent, enterprise-grade bots that let you maintain control of your data. Build any type of bot—from a Q&A bot to your own branded virtual assistant. Use a comprehensive, open-source SDK and tools to easily connect your bot across popular channels and devices. Give your bot the ability to speak, listen, and understand your users with native integration of Azure Cognitive Services.

They have an intuitive visual interface for those without a coding background, but developers will like the editable front-end and customization options. While you can build a bot for free, a lot of the more complex (and interesting) tools are only available with Chatfuel Pro accounts. Either way, it might be helpful to know that Chatfuel integrates with Hootsuite Inbox using the Facebook Messenger handover protocol.